Last year at Transworld we bought a kit from HOT WIRE FOAM FACTORY which cuts/melts thur many different styrofoams. We used the white and pink stuff last year this kit worked like a charm. visit there site at www.hotwirefoamfactory.com and they also are going to be at transworld this year again which you can buy a kit that same day and walk out the doors with it.

Roy, there are lots of good resources online. Demand products is a company I like to use.
http://www.demandproducts.com/
The aforementioned Hot wire foam factory has great starter stuff and a nice bow carving too l that is excellent and affordable. their table cutter is nice also.
Sandblasting is also an excellent carving technique. a soldering iron is also very useful for general work. dry brushing is a painting technique that I think is very compatible with foam work, it is a must know.
your asking alot here so I may pop on later and give more tips as I think of them.
the kind of foam is up to you, I find the blue and pink stuff great for sign work and props that can be layered up , the white stuff is easier to find in big blocks so its used most often for sculpting and big stuff. if you poke around in your phone book under styrofoam, polystyrene and even insulation you will be able to find a local provider. I have to drive 30 min to get mine and a 3'x4'x8' block costs about $270 but If i want that sliced in any straight lines (even 1'' slices ) the cutting is free.
The castle on this website was covered in foam and sculpted with soldering iron and heat gun. I built it in 03 and it is still going strong. www.huntmonsters.com it is coated with spray on acrylic stucco.
If you need any specific help feel free to PM me
Allen H

Allen, great resources... thanks!

Kel

One more thing...
Polystyrene foam comes in different densities and is referred to as such. so 5lb foam refers to one cubic ft of foam and weighs 5 lbs. one cubis ft of 3lb foam weighs 3lbs. If you arent familiar with the terminology then it can get confusing.
Allen H